quoted

Isn't AE_VERSION_1 something fixed once you publish your features?
If it can't be changed, why not simply remove the features from
`hw_features' instead of having to implement this ndo?

There could be a case where the feature is supported by the SoC
and therefore it is already part of the 'hw_features' but it has been
say DISABLED or ENABLED by ethtool. In such a case, we need to
make sure we strike off that feature from the 'features' flag.

Therefore, we need this leg I suppose. Let me know If I am missing
something here or there is a gap in my understanding.

Look at ethtool_set_features() - if something isn't listed in hw_features,
you're not support to be able to change it.

If you can make a one-time decision when registering the netdevice
whether this feature is supported by HW or not [assuming AE_VERSION_1
is available at that point and can't later change] than it's the better alternative.

Cheers,
Yuval